// Tencent is pleased to support the open source community by making ncnn available.
//
// Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
//
// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// https://opensource.org/licenses/BSD-3-Clause
//
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

#ifndef NCNN_LAYER_H
#define NCNN_LAYER_H
#include "platform.h" 
#include <stdio.h>
#include <string>
#include <vector>
#include "mat.h"
#include "paramdict.h"
#include "platform.h"

namespace ncnn {

    class Layer {
    public:
        // empty
        Layer();

        // virtual destructor
        virtual ~Layer();

        // load layer specific parameter from parsed dict
        // return 0 if success
        virtual int load_param(const ParamDict &pd);

#if NCNN_STDIO

        // load layer specific weight data from model file
        // return 0 if success
        virtual int load_model(FILE *binfp);

#endif // NCNN_STDIO

        // load layer specific weight data from memory
        // memory pointer is 32-bit aligned
        // return 0 if success
        virtual int load_model(const unsigned char *&mem);

    public:
        // one input and one output blob
        bool one_blob_only;

        // support inplace inference
        bool support_inplace;

    public:
        // implement inference
        // return 0 if success
        virtual int forward(const std::vector<Mat> &bottom_blobs, std::vector<Mat> &top_blobs) const;

        virtual int forward(const Mat &bottom_blob, Mat &top_blob) const;

        // implement inplace inference
        // return 0 if success
        virtual int forward_inplace(std::vector<Mat> &bottom_top_blobs) const;

        virtual int forward_inplace(Mat &bottom_top_blob) const;

    public:
#if NCNN_STRING
        // layer type name
        std::string type;
        // layer name
        std::string name;
#endif // NCNN_STRING
        // blob index which this layer needs as input
        std::vector<int> bottoms;
        // blob index which this layer produces as output
        std::vector<int> tops;
    };

// layer factory function
    typedef Layer *(*layer_creator_func)();

    struct layer_registry_entry {
#if NCNN_STRING
        // layer type name
        const char *name;
#endif // NCNN_STRING
        // layer factory entry
        layer_creator_func creator;
    };

#if NCNN_STRING

// get layer type from type name
    int layer_to_index(const char *type);

#endif // NCNN_STRING

// create layer from layer type
    Layer *create_layer(int index);

#define DEFINE_LAYER_CREATOR(name) \
    ::ncnn::Layer* name##_layer_creator() { return new name; }

} // namespace ncnn

#endif // NCNN_LAYER_H
